Starfall has fun, educational activities for children. It has a free portion for a large amount of their resources.
Dr. Jean Feldman has been in education for over 40 years and has written several books. Her website has lots of good information as well as some free activites.
This website has a lot of interactive educational games for young learners.
Jack Hartmann has numerous fun and educational songs for math and literacy.
Dr. Jean Feldman is amazing! I have had the priviledge to see her several times at different events. She has created so many fun, educational things for young learners that are developmentally appropriate!